This invention relates to electrostatographic reproduction machines, and more particularly to a compact electrostatographic reproduction machine lacking a separate machine frame to which components are mounted, but which comprises separately framed, mutually aligning modules for enabling high level sourcing and quick non-specialized tools assembly and disassembly of the machine.
Generally, the process of electrostatographic reproduction includes charging a photoconductive member to a substantially uniform potential so as to sensitize the surface thereof. A charged portion of the photoconductive surface is exposed at an exposure station to a light image of an original document being reproduced. Typically, hard copy jobs, each comprising of a set of sheets of original documents are held and automatically handled by a recirculating document handler to the exposure station. Document handlers used with electrostatographic reproduction machines frequently are provided with a recirculating mode whereby stacked documents are withdrawn individually and sequentially from an input holding tray, passed to the exposure station, and then are outputted back to the holding tray for subsequent recirculation in the previous manner. Some document handlers also invert the documents so that a duplex document may be imaged on both sides.
Exposing a document sheet fed for example by a document handler to the exposure station records an electrostatic latent image onto the photoconductive member. After the electrostatic latent image is recorded as such, the latent image is subsequently developed using a development apparatus by bringing a charged dry or liquid developer material into contact with the latent image. Two component and single component developer materials are commonly used. A typical two-component dry developer material has magnetic carrier granules with fusible toner particles adhering triobelectrically thereto. A single component dry developer material typically comprising toner particles only can also be used. The toner image formed by such development is subsequently transferred to a copy sheet, on which it is then heated and permanently fused in order to form a "hardcopy" of the original image.
Electrostatographic reproduction machines based on this process, whether digital or light lens, are now commonly used in business environments, and the trend is more and more towards their use as desktop or personal reproduction machines or copiers. Conventionally, such digital and light lens electrostatographic reproduction machines contain selective electrostatographic components or susbsystems that are designed for mounting to a unitary machine frame in order to assure rigidity and subsystem to subsystem alignment. Typically, such a machine and its unitary frame is produced and integrated by one producer, even if some of its subsystems are produced by others for such subsequent integration. Invariably, some of the most each subsystem is likely to be lost when mounting, aligning and integration is carried out by another. It is therefore difficult to optimize the technical and operational quality, the total cost and the machine delivery time for such machines.
There is therefore a need for a compact electrostatographic reproduction machine that is comprised of separately framed modules that are each designed and supplied as self-standing, specable (i.e. separately specified with interface inputs and outputs), testable, and shippable module units, and that is specifically partitioned for enabling operative integration of all the critical electrostatographic functions, upon mere assembly without resort to subsequent alignment and adjustments. Advantageously, each such self-standing, specable, testable, and shippable module unit specifically allows for high level sourcing of the units to a small set of module-specific skilled production suppliers, thus optimizing the technical and operative quality, the total cost, and the time of delivering of the final product, the machine.